The present invention relates to a copying method for bookbinding which uses a copier having a double-face copying function and a variable magnification copying function and, more particularly, to a copying method for binding papers at their center which carry duplicates of original documents thereon.
In a copier of the type described, where it is desired to produce a plurality of copies for each of a plurality of documents, use has been made of a sorter to sort copies in the order of pages and a stitcher to bind the copies along their aligned edges.
The problem with such a prior art system is that binding or stitching relatively large sheets such as those of format A3 or B4 along their aligned edges results in a booklet which occupies a substantial space or area when opened and, so, is awkward to handle. In addition, while relatively large sheets are sometimes double-folded after being bound along the edge in order to save the space for storage, folding bound sheets double together not only degrades their appearance in storage but also makes information carried in the folded portions difficult to see due to the folds.
Although the problem mentioned above may be overcome by binding papers at their center, such requires that the positions of documents to be duplicated on papers be constantly taken into consideration. In addition, where the documents and papers are equal in size, a single document has to appear in a spread position of the resulting booklet which is bound at the center.
Meanwhile, if papers after copying are each double-folded at the center, then laid one upon another, and then bound at their center, the resulting booklet will require a minimum of space for storage and a minimum of area when spread.
When it is desired to bind papers at the center as described above, the prerequisite is that documents be duplicated on both faces of each paper. Duplicating documents on both faces of each paper and center-binding the papers by use of a prior art copier is quite inefficient and consumes a prohibitive amount of time.